In many multi-site communication systems today, communication units make neighbor site measurements to select a handoff site. The communication unit relies on a serving site for communication service, but as the communication unit moves through the serving site's wireless coverage area, the quality of the wireless connection with that serving site may deteriorate. To address this problem, the communication unit hands off to a neighboring site, whereby the neighboring site becomes the new serving site of the communication unit.
To select a neighboring site to which to handoff, communication units often will perform neighbor site measurements that involve, for example, determining the signal strength of signals received from neighboring sites. Typically, measurements of neighboring site signals are performed with some regularity. With up-to-date neighbor site measurements, the changing wireless environment can be monitored and a handoff performed before communication service is interrupted.
To perform neighbor site measurements, a communication unit must receive signals from neighboring base sites. For communication units that can receive only one signal at a time, neighbor site measurements must be performed at the expense of receiving signaling from the serving site. During a period of extended data transfer, such a communication device often must delay the data transfer in order to make neighbor site measurements. Thus, data throughput is reduced and quality of service is lowered.
Therefore, a need exists for an apparatus and method for performing neighbor site measurements that reduces such data transfer delays.